1. Field of the Invention
The present invention relates to an ophthalmic photographing apparatus for illuminating an eye to be tested, observing it and photographing it.
2. Related Background Art
In a prior art ophthalmic photographing apparatus such as a slit lamp microscope, a compact construction is needed for clinical examination. Accordingly, in order to enhance the operability in the clinical examination, not only a camera but also a photographic recorder may be removably attached to a monitoring microscope of the ophthalmic photographing apparatus so that it may be used as a clinical slit lamp when it is not used for photographing. Because of such a construction, the ophthalmic photographing apparatus such as the slit ramp microscope usually does not have an exposure determination unit. Thus, a user experimentarily determines the exposure by his/her decision based on an area to be photographed and a magnification. As a result, proper exposure is difficult to attain. Recently, an ophthalmic photographing apparatus which detects a photographing magnification and other photographing condition and calculates proper exposure has been proposed as disclosed in Japanese Laid-Open Patent Application No. 56-72841, an ophthalmic photographing apparatus which detects the magnification and calculates the proper exposure is now commercially available.
In the prior art ophthalmic photographing apparatus which detects the photographing magnification and other photographing conditions and calculates the proper exposure, it is required to built in a detection unit for a magnification signal. As a result, the apparatus is of large size and it is exclusively used for photographing because the photographing apparatus is fixed and it cannot be used for clinical examination.
When the photographing apparatus is detachable in order to enhance the operability in the clinical examination, electrical contacts are formed in a mount. Thus, the attachment and detachment of the photographic recorder are difficult to attain because of the contact pressures, and the contacts are apt to be deteriorated.